38 CFR § 3.401 - Veterans.
Awards of pension or compensation payable to or for a veteran will be effective as follows:
(a) Aid and attendance and housebound benefits.
(1) Except as provided in § 3.400(o)(2), the date of receipt of claim or date entitlement arose, whichever is later. However, when an award of pension or compensation based on an original or supplemental claim is effective for a period prior to the date of receipt of the claim, any additional pension or compensation payable by reason of need for aid and attendance or housebound status shall also be awarded for any part of the award's retroactive period for which entitlement to the additional benefit is established.
(2) Date of departure from hospital, institution, or domiciliary.
(3) Spouse, additional compensation for aid and attendance: Date of receipt of claim or date entitlement arose, whichever is later. However, when an award of disability compensation based on an original or supplemental claim is effective for a period prior to date of receipt of the claim additional disability compensation payable to a veteran by reason of the veteran's spouse's need for aid and attendance shall also be awarded for any part of the award's retroactive period for which the spouse's entitlement to aid and attendance is established.
(b) Dependent, additional compensation or pension for. Latest of the following dates:
(1) Date of claim. This term means the following, listed in their order of applicability:
(ii) Date notice is received of the dependent's existence, if evidence is received within 1 year of the Department of Veterans Affairs request.
(2) Date dependency arises.
(3) Effective date of the qualifying disability rating provided evidence of dependency is received within 1 year of notification of such rating action.
(c) Divorce of veteran and spouse. See § 3.501(d).
(e) Retirement pay (§ 3.750) - (1) Election. Date of entitlement if timely filed. Subject to prior payments of retirement pay.
(2) Waiver. Day following date of discontinuance or reduction of retirement pay.
(3) Reelection. Day the reelection is received by the Department of Veterans Affairs.
(g) Tuberculosis, special compensation for arrested. As of the date the graduated evaluation of the disability or compensation for that degree of disablement combined with other service-connected disabilities would provide compensation payable at a rate less than $67. See § 3.350(g).
(h) Temporary increase “General Policy in Rating,” 1945 Schedule for Rating Disabilities -
(1) Section 4.29 of this chapter. Date of entrance into hospital, after 21 days of continuous hospitalization for treatment.
(2) Section 4.30 of this chapter. Date of entrance into hospital, after discharge from hospitalization (regular or release to non-bed care).
(i) Increased disability pension based on attainment of age 78. First day of the month during which veteran attains age 78.